350 research outputs found

    When music speaks: An aoustic study of the speech surrogacy of the Nigerian Dùndún Talking Drum

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    Yorùbá dùndún drumming is an oral tradition which allows for manipulation of gliding pitch contours in ways that correspond to the differentiation of the Yorùbá linguistic tone levels. This feature enables the drum to be employed as both a musical instrument and a speech surrogate. In this study, we examined four modes of the dùndún talking drum, compared them to vocal singing and talking in the Yorùbá language, and analyzed the extent of microstructural overlap between these categories, making this study one of the first to examine the vocal surrogacy of the drum in song. We compared the fundamental frequency, timing pattern, and intensity contour of syllables from the same sample phrase recorded in the various communicative forms and we correlated each vocalization style with each of the corresponding drumming modes. We analyzed 30 spoken and sung verbal utterances and their corresponding drum and song excerpts collected from three native Yorùbá speakers and three professional dùndún drummers in Nigeria. The findings confirm that the dùndún can very accurately mimic microstructural acoustic temporal, fundamental frequency, and intensity characteristics of Yorùbá vocalization when doing so directly, and that this acoustic match systematically decreases for the drumming modes in which more musical context is specified. Our findings acoustically verify the distinction between four drumming mode categories and confirm their acoustical match to corresponding verbal modes. Understanding how musical and speech aspects interconnect in the dùndún talking drum clarifies acoustical properties that overlap between vocal utterances (speech and song) and corresponding imitations on the drum and verifies the potential functionality of speech surrogacy communications systems

    Paradoxical popups: Why are they hard to catch?

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    Even professional baseball players occasionally find it difficult to gracefully approach seemingly routine pop-ups. This paper describes a set of towering pop-ups with trajectories that exhibit cusps and loops near the apex. For a normal fly ball, the horizontal velocity is continuously decreasing due to drag caused by air resistance. But for pop-ups, the Magnus force (the force due to the ball spinning in a moving airflow) is larger than the drag force. In these cases the horizontal velocity decreases in the beginning, like a normal fly ball, but after the apex, the Magnus force accelerates the horizontal motion. We refer to this class of pop-ups as paradoxical because they appear to misinform the typically robust optical control strategies used by fielders and lead to systematic vacillation in running paths, especially when a trajectory terminates near the fielder. In short, some of the dancing around when infielders pursue pop-ups can be well explained as a combination of bizarre trajectories and misguidance by the normally reliable optical control strategy, rather than apparent fielder error. Former major league infielders confirm that our model agrees with their experiences.Comment: 28 pages, 10 figures, sumitted to American Journal of Physic

    The potential determinants of young people's sense of justice: an international study

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    This paper uses reports from 13,000 Grade Nine pupils in five countries to examine issues such as whether they were treated fairly at school, trust their teachers and adults in wider society, are willing to sacrifice teacher attention to help others, and support the cultural integration of recent immigrants. Using such reports as ‘outcomes’ in a multi‐stage regression model, it is clear that they are largely unrelated to school‐level pupil mix variables. To some extent, these outcomes are stratified by pupil and family background in the same way for all countries. However, the largest association is with pupil‐reported experience of interactions with their teachers. Teachers appear to be a major influence on young people's sense of justice and the principles they apply in deciding whether something is fair. The paper concludes by suggesting ways in which schools and teachers could take advantage of this finding

    Improving water productivity in the Australian Grains industry—a nationally coordinated approach

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    Improving the water-limited yield of dryland crops and farming systems has been an underpinning objective of research within the Australian grains industry since the concept was defined in the 1970s. Recent slowing in productivity growth has stimulated a search for new sources of improvement, but few previous research investments have been targeted on a national scale. In 2008, the Australian grains industry established the 5-year, AU$17.6 million, Water Use Efficiency (WUE) Initiative, which challenged growers and researchers to lift WUE of grain-based production systems by 10%. Sixteen regional grower research teams distributed across southern Australia (300–700 mm annual rainfall) proposed a range of agronomic management strategies to improve water-limited productivity. A coordinating project involving a team of agronomists, plant physiologists, soil scientists and system modellers was funded to provide consistent understanding and benchmarking of water-limited yield, experimental advice and assistance, integrating system science and modelling, and to play an integration and communication role. The 16 diverse regional project activities were organised into four themes related to the type of innovation pursued (integrating break-crops, managing summer fallows, managing in-season water-use, managing variable and constraining soils), and the important interactions between these at the farm-scale were explored and emphasised. At annual meetings, the teams compared the impacts of various management strategies across different regions, and the interactions from management combinations. Simulation studies provided predictions of both a priori outcomes that were tested experimentally and extrapolation of results across sites, seasons and up to the whole-farm scale. We demonstrated experimentally that potential exists to improve water productivity at paddock scale by levels well above the 10% target by better summer weed control (37–140%), inclusion of break crops (16–83%), earlier sowing of appropriate varieties (21–33%) and matching N supply to soil type (91% on deep sands). Capturing synergies from combinations of pre- and in-crop management could increase wheat yield at farm scale by 11–47%, and significant on-farm validation and adoption of some innovations has occurred during the Initiative. An ex post economic analysis of the Initiative estimated a benefit : cost ratio of 3.7 : 1, and an internal return on investment of 18.5%. We briefly review the structure and operation of the initiative and summarise some of the key strategies that emerged to improve WUE at paddock and farm-scale

    The diffusion of policy in contexts of practice : flexible delivery in Australian vocational education and training

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    Significant changes have occurred over the last decade within the Australian Vocational Education and Training (VET) system. Not least amongst these has been a shift from a predominantly traditional face-to-face classroom model of programme delivery to more flexible models informed by the needs of clients. To lead this revolution, in 1991 the Australian Commonwealth and State Ministers for Training established the Flexible Delivery Working Party. A series of reports followed that sought to develop a policy framework, including a definition of flexible delivery, and its principles and characteristics. Despite these efforts, project funding and national staff development initiatives, several difficulties have been experienced in the ‘take-up’ of flexible delivery; problems that we argue are related to how the dissemination of innovative practice is conceived. Specifically, the literature and research on the diffusion of innovations points to the efficacy of informal social networks ‘in which individuals adopt the new idea as a result of talking with other individuals who have already adopted it’ (Valente, 1995, p. ix). Following a discussion of these issues, the article concludes by arguing the need for research of innovative practice transfer within VET in Australia, using qualitative case study in order to develop an in-depth and rich description of the process, and facilitate greater understanding of how it works in practice

    Thin Polymer Brush Decouples Biomaterial's Micro-/Nano-Topology and Stem Cell Adhesion

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    Surface morphology and chemistry of polymers used as biomaterials, such as tissue engineering scaffolds, have a strong influence on the adhesion and behavior of human mesenchymal stem cells. Here we studied semicrystalline poly(ε-caprolactone) (PCL) substrate scaffolds, which exhibited a variation of surface morphologies and roughness originating from different spherulitic superstructures. Different substrates were obtained by varying the parameters of the thermal processing, i.e. crystallization conditions. The cells attached to these polymer substrates adopted different morphologies responding to variations in spherulite density and size. In order to decouple substrate topology effects on the cells, sub-100 nm bio-adhesive polymer brush coatings of oligo(ethylene glycol) methacrylates were grafted from PCL and functionalized with fibronectin. On surfaces featuring different surface textures, dense and sub-100 nm thick brush coatings determined the response of cells, irrespective to the underlying topology. Thus, polymer brushes decouple substrate micro-/nano-topology and the adhesion of stem cells

    Enhanced transfection of cell lines from Atlantic salmon through nucoleofection and antibiotic selection

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    Background Cell lines from Atlantic salmon kidney have made it possible to culture and study infectious salmon anemia virus (ISAV), an aquatic orthomyxovirus affecting farmed Atlantic salmon. However, transfection of these cells using calcium phosphate precipitation or lipid-based reagents shows very low transfection efficiency. The Amaxa Nucleofector technology™ is an electroporation technique that has been shown to be efficient for gene transfer into primary cells and hard to transfect cell lines. Findings Here we demonstrate, enhanced transfection of the head kidney cell line, TO, from Atlantic salmon using nucleofection and subsequent flow cytometry. Depending on the plasmid promoter, TO cells could be transfected transiently with an efficiency ranging from 11.6% to 90.8% with good viability, using Amaxa's cell line nucleofector solution T and program T-20. A kill curve was performed to investigate the most potent antibiotic for selection of transformed cells, and we found that blasticidin and puromycin were the most efficient for selection of TO cells. Conclusions The results show that nucleofection is an efficient way of gene transfer into Atlantic salmon cells and that stably transfected cells can be selected with blasticidin or puromycin

    Smooth Muscle Cell Phenotype Modulation and Contraction on Native and Cross-Linked Polyelectrolyte Multilayers

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    Smooth muscle cells convert between a motile, proliferative “synthetic ” phenotype and a sessile, “contractile ” phenotype. The ability to manipulate the phenotype of aortic smooth muscle cells with thin biocompatible polyelectrolyte multilayers (PEMUs) with common surface chemical characteristics but varying stiffness was investigated. The stiffness of (PAH/ PAA) PEMUs was varied by heating to form covalent amide bond cross-links between the layers. Atomic force microscopy (AFM) showed that cross-linked PEMUs were thinner than those that were not cross-linked. AFM nanoindentation demonstrated that the Young’s modulus ranged from 6 MPa for hydrated native PEMUs to more than 8 GPa for maximally cross-linked PEMUs. Rat aortic A7r5 smooth muscle cells cultured on native PEMUs exhibited morphology and motility of synthetic cells and expression of the synthetic phenotype markers vimentin, tropomyosin 4, and nonmuscle myosin heavy chain IIB (nmMHCIIB). In comparison, cells cultured on maximally cross-linked PEMUs exhibited the phenotype markers calponin, smooth muscle myosin heavy chain (smMHC), myocardin, transgelin, and smooth muscle R-actin (smActin) that are characteristic of the smooth muscle “contractile ” phenotype. Consistent with those cells being “contractile”, A7r5 cells grown on cross-linked PEMUs produced contractile force when stimulated with a Ca2+ ionophore
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